It is well-known to cast concrete objects which are round, circular, square, rectangular or any other well-defined linear or symmetrical shape, such as walls, floor slabs, pillars, tiles and a few other constructional elements. These objects are designed with a relatively simple geometry in order to provide for a relatively inexpensive construction material.
Concrete objects are manufactured by casting wet concrete in a formworks, and removing the formworks after the concrete has hardened. The shape of the formworks defines the shape of the final concrete product. Furthermore, the formworks needs to support the weight of the wet concrete poured in the formworks to form the final concrete product. Since the weight of wet concrete is substantial, formworks are typically made of wood or steel.
These traditional formworks are time consuming and expensive to erect. In particular the manufacture of concrete objects with curved surfaces requires the use of elaborate and complicated formworks. It is furthermore noted that the form defining function and the support function of the formworks are closely related. Thus, a form change of the product cavity typically requires a significant change in the design of the overall formworks.
Formworks comprising fabric sections are also known. Fabric material is used for providing curved surfaces because the material is easier to handle, i.e. bend and cut, than wooden or steel plates. The fabric material is typically supported by a steel support frame of concrete reinforcing members. The strength of the fabric, the support frame, and the connections between the fabric and the support frame are critical since they form the product mould, and thus have to support the weight of the wet concrete after the product mould has been filled. Therefore, the application of these kinds of formworks is limited to the construction of simple shapes such as columns and foundation footing.